FIG 4.
Effect of rifabutin, clarithromycin, and tigecycline combinations on M. abscessus viability. Rifabutin was added to M. abscessus cultures at 1× (6.3 mg/liter), 1/2×, 1/4×, 1/8×, or 1/16× MIC in combinations of clarithromycin and tigecycline at 1× MICs of tigecycline (0.8 mg/liter) and clarithromycin (0.4 mg/liter) (A), 1/4× MICs of tigecycline and clarithromycin (B), 1/8× MICs of tigecycline and clarithromycin (C), or lung Cmax tigecycline (1/2× MIC) and clarithromycin (50× MIC) (D). CFU were determined at 24-h intervals after antibiotic addition. The dashed line represents the limit of detection. Data points are the means from three replicates with standard deviations presented as error bars.